In prior art, systems and methods are known in the field of rapid prototyping and laser sintering, wherein a granular material is deposited in separate layers on a platform in a container, and is hardened locally and selectively layer by layer, so as to build up a solidified mold body from the granular material. For doing so, the bottom of the container, which is formed by the platform and which is height-adjustable, is lowered by one layer thickness respectively before application of a new layer. Once all necessary layers are applied and selectively hardened, the mold body formed in this manner may be removed, for example in a removal station, by removing the non-solidified granular material.
A removable or interchangeable container in which a mold body can be built in this manner is for example known from EP 1037739 B1. The interchangeable container disclosed therein comprises a container bottom forming a workpiece platform that can be moved vertically within the container. The interchangeable container comprises engagement recesses in a rear side wall, through which one or more support arms reach underneath the workpiece platform, the support arms being height-adjustably mounted to the building station of the system. As soon as the forming of a mold body is complete, the workpiece platform is locked and the whole interchangeable container including the mold body can be removed from the building station of the system.
Alternatively, a lifting device may be integrated in the interchangeable container under the workpiece platform according to cited prior art for the height-adjustability of the same.
However, interchangeable containers designed in this manner have the disadvantage that they have to comprise sufficiently large and long engagement recesses in the embodiment without an integrated lifting device, in order that the support arms at the building station of the system can engage therethrough. In addition, locking devices are required, in order to allow the workpiece platform to remain at an unchanged level when the interchangeable container is removed from the building station, wherein then the support arms are not disposed underneath the workpiece platform anymore. On the other hand, the interchangeable container comprising a lifting device integrated under the workpiece platform is very complex, whereby the interchangeable container becomes large and heavy and is therefore difficult to handle when changing or moving from one station to another.